It appears that the trailing `$` for object references in publicly accessible system catalog views indicates an _internal_ system catalog view. I say this because when looking at the source column for `sys.objects`, the source is not `sys.objects$` but instead is a combination of the following three internal tables:
1. `sysschobjs`
1. `syssingleobjrefs`
1. `syspalnames`
When looking at the source columns for `sys.objects$`, they are the same sources as noted for `sys.objects` for the same columns, but there are plenty more columns in `sys.objects$` (51 compared to 17 for `sys.objects`). Then, looking at the source columns for one of the base objects, `syspalnames`, the sources were finally that same object: `sys.syspalnames`.
While I can get the definition of `sys.objects`, I cannot get the definition of `sys.objects$`.
This pattern holds true for `sys.configurations` as well. Its definition points to `sys.configurations$`, yet the columns are all either expressions or have an actual source of `sys.sysobjvalues`. And the source for all columns in `sys.sysobjvalues` is itself: `sys.sysobjvalues`.
Below is the research output (some of it; not enough space here to put it all in), done on SQL Server 2012.
I used the following query via a DAC connection. The final input parameter value of `1` is import as it enables the reporting of the "source" info.
<!-- language: lang-sql -->
USE [tempdb];
SELECT [name], [source_database], [source_schema], [source_table], [source_column],
[is_computed_column]
FROM sys.dm_exec_describe_first_result_set(N'SELECT * FROM sys.objects$', NULL, 1)
ORDER BY [column_ordinal] ASC;
The command-line was:
<!-- language: lang-none -->
sqlcmd -A -E -Q "USE [tempdb]; SELECT [name], [source_database], [source_schema], [source_table], [source_column], [is_computed_column] FROM sys.dm_exec_describe_first_result_set(N'SELECT * FROM sys.objects$', NULL, 1) ORDER BY [column_ordinal] ASC;" -o InternalViews_SysObjects$.txt -W
---
**sys.objects**
<!-- language: lang-none -->
name source_database source_schema source_table source_column is_computed_column
---- --------------- ------------- ------------ ------------- ------------------
name tempdb sys sysschobjs name 0
object_id tempdb sys sysschobjs id 0
principal_id tempdb sys syssingleobjrefs indepid 0
schema_id tempdb sys sysschobjs nsid 0
parent_object_id tempdb sys sysschobjs pid 0
type NULL NULL NULL NULL 1
type_desc mssqlsystemresource sys syspalnames name 0
create_date tempdb sys sysschobjs created 0
modify_date tempdb sys sysschobjs modified 0
is_ms_shipped NULL NULL NULL NULL 1
is_published NULL NULL NULL NULL 1
is_schema_published NULL NULL NULL NULL 1
depid tempdb sys syssingleobjrefs depid 0
class tempdb sys syssingleobjrefs class 0
depsubid tempdb sys syssingleobjrefs depsubid 0
class mssqlsystemresource sys syspalnames class 0
value mssqlsystemresource sys syspalnames value 0
**sys.objects$**
<!-- language: lang-none -->
name source_database source_schema source_table source_column is_computed_column
---- --------------- ------------- ------------ ------------- ------------------
name tempdb sys sysschobjs name 0
object_id tempdb sys sysschobjs id 0
principal_id tempdb sys syssingleobjrefs indepid 0
schema_id tempdb sys sysschobjs nsid 0
parent_object_id tempdb sys sysschobjs pid 0
type tempdb sys sysschobjs type 0
type_desc mssqlsystemresource sys syspalnames name 0
property tempdb sys sysschobjs intprop 0
create_date tempdb sys sysschobjs created 0
modify_date tempdb sys sysschobjs modified 0
is_ms_shipped NULL NULL NULL NULL 1
is_auto_dropped NULL NULL NULL NULL 1
is_system_named NULL NULL NULL NULL 1
is_published NULL NULL NULL NULL 1
is_schema_published NULL NULL NULL NULL 1
is_cycling NULL NULL NULL NULL 1
lock_on_bulk_load NULL NULL NULL NULL 1
is_disabled NULL NULL NULL NULL 1
is_auto_executed NULL NULL NULL NULL 1
is_activation_enabled NULL NULL NULL NULL 1
has_opaque_metadata NULL NULL NULL NULL 1
is_not_for_replication NULL NULL NULL NULL 1
is_receive_enabled NULL NULL NULL NULL 1
is_cached NULL NULL NULL NULL 1
is_not_trusted NULL NULL NULL NULL 1
is_enqueue_enabled NULL NULL NULL NULL 1
with_check_option NULL NULL NULL NULL 1
is_retention_enabled NULL NULL NULL NULL 1
has_unchecked_assembly_data NULL NULL NULL NULL 1
update_referential_action NULL NULL NULL NULL 1
delete_referential_action NULL NULL NULL NULL 1
is_replicated NULL NULL NULL NULL 1
is_execution_replicated NULL NULL NULL NULL 1
has_replication_filter NULL NULL NULL NULL 1
is_repl_serializable_only NULL NULL NULL NULL 1
is_merge_published NULL NULL NULL NULL 1
skips_repl_constraints NULL NULL NULL NULL 1
is_sync_tran_subscribed NULL NULL NULL NULL 1
uses_ansi_nulls NULL NULL NULL NULL 1
null_on_null_input NULL NULL NULL NULL 1
uses_database_collation NULL NULL NULL NULL 1
is_tracked_by_cdc NULL NULL NULL NULL 1
large_value_types_out_of_row NULL NULL NULL NULL 1
lock_escalation_option NULL NULL NULL NULL 1
is_poison_message_handling_enabled NULL NULL NULL NULL 1
is_filetable NULL NULL NULL NULL 1
depid tempdb sys syssingleobjrefs depid 0
class tempdb sys syssingleobjrefs class 0
depsubid tempdb sys syssingleobjrefs depsubid 0
class mssqlsystemresource sys syspalnames class 0
value mssqlsystemresource sys syspalnames value 0
**sys.syspalnames**
<!-- language: lang-none -->
name source_database source_schema source_table source_column is_computed_column
---- --------------- ------------- ------------ ------------- ------------------
class mssqlsystemresource sys syspalnames class 0
value mssqlsystemresource sys syspalnames value 0
name mssqlsystemresource sys syspalnames name 0